3 Functions of Body FluidMedium for transportNeeded for cellular metabolismSolvent for electrolytes and other constituentsHelps maintain body temperatureHelps digestion and eliminationActs as a lubricant

8 Variations in Body FluidsElderly: Have lower % of total body fluid than younger adultsWomen: Have lower % total body fluid than menWHY DO YOU THINK THIS IS ?????Increased risk for fluid/electrolyte imbalance with decreased muscle since muscle cells hold more waterMuscle tissue has more H20 content THAN adipose tissue

10 Consider this….Age variations exist in regards to H20 content of fluid compartmentsInfants = 60% of H20 is found in ECF 40% of H20 is found in ICFWhat might this mean in regards to fluid loss for an infant?This is reverse of adults THEREFORE the infant is more susceptible to fluid lossReverse of adults!Infant MORE PRONE to fluid LOSS!

11 Fluid Balance Dynamic processBalance between body fluids and electrolytesAttraction between ions (electrolytes) and water (fluids) causes fluids to move across membranes and leave their compartments.SEE NEXT SLIDES FOR IN-DEPTH

12 Solvent (H20) MovementCell membranes are semipermeable allowing water to pass throughOsmosis- major way fluids transported Water shifts from low solute concentration to high solute concentration to reach homeostasis (balance).Water is a solventConcentration of particles in solution (pulling action = osmolarity)Isotonic have almost same osmolarity as plasma therefore there is no pull

13 Osmolarity Concentration of particles in solutionThe greater the concentration (Osmolarity) of a solution, the greater the pulling force (Osmotic pressure)Normal serum (blood) osmolarity = mOSM/kgA solution that has HIGH osmolarity is one that is > serum osmolarity = HYPERTONIC solutionA solution that has LOW osmolarity is one that is < serum osmolarity = HYPOTONIC solutionA solution that has equal osmolarity as serum = ISOTONIC solutionOsmosis, by the way, is the reason that drinking salt water will kill you.The HIGH osmolarity salt water in the GI system rapidly pulls water into the GI system and excretion – rapidly dehydrating cellsSEE NEXT SLIDES FOR FURTHER DISCUSSION

14 Hypertonic FluidsHypertonic fluids have a higher concentration of particles (high osmolality) than ICFThis higher osmotic pressure shifts fluid from the cells into the ECFTherefore Cells placed in a hypertonic solution will shrink

17 Hypotonic Fluids Used to “dilute” plasma particularly in hypernatremiaTreats cellular dehydrationDo not use for pts with increased ICP risk or third spacing risk0.45%NS0.33%NS

18 Isotonic FluidIsotonic fluids have the same concentration of particles (osmolality) as ICF ( mOsm/L)Osmotic pressure is therefore the same inside & outside the cellsCells neither shrink nor swell in an isotonic solution, they stay the sameICF intracellular fluid - fluid inside the cellD5W isotonic /Normal saline solution is isotonic because it has almost the same concentration of sodium as blood.Used to replace Ecvlume

20 Other Osmotic Factors ALBUMIN ( a serum protein )Albumin in the serum has osmotic properties called colloid pressureAlbumin pulls H20 from the interstitial compartments into the intravascular compartments (serum). Helps to maintain BP.Persons with low serum albumin levels tend to retain fluid in their interstitial layers. What abnormal assessments might you find in the client with low serum albumin levels?Edema, hypotension

22 Consider this….When tissue injury occurs, proteins pathologically leak from the intravascular space into the intersititial space. Termed: Third spacingThis explains __________ as a sign of the inflammatory process.EDEMAEDEMA

23 Solute Movement - DiffusionMovement of solutes from high concentration to low concentrationIt is a PASSIVE movement DOWN the concentration gradiant. (requires no energy)Many body processes use diffusion. Example: O2 and CO2 exchangeRate is affected by: concentration gradiant, permeability-surface area-thickness of membranes, and size of particles. (Fick’s Law)Filtration- from pressure to low pressure

25 Filtration Solvent AND solute movementPassage from an area of High Pressure to an area of Low Pressure Termed: Hydrostatic PressureExample: Arterioles have higher pressure than ICF Fluid, oxygen and nutrients move into cells Venules have lower pressure than ICF Fluid, carbon dioxide and wastes move out of cells

40 Clinical ApplicationYou have been assigned to care for an 80y.o. client admitted with hypernatremia that has an IV infusing 0.45% 100ml/hr via pump and an indwelling urinary catheter. At 11am you assess an output in the urinary drainage bag of 150ml dk amber urine. You also notice that the client is SOB while speaking on the phone to her daughter.What do you think is happening??What will you do??

41 Want more Information??? CHECK OUT THESUMMARYWant more Information??? CHECK OUT THEWEBLINKSFor Chapter 41 on EVOLVE

42 Electrolytes Work with fluids to keep the body healthy and in balanceThey are solutes that are found in various concentrations and measured in terms of milliequivalent (mEq) unitsCan be negatively charged (anions) or positively charged (cations)For homeostasis body needs: Total body ANIONS = Total body CATIONS1 mEq MILLIEQUIVALENT = 1 MG OF HYDROGEN

43 Electrolytes Cations Positively charged Sodium Na+ Potassium K+Calcium Ca++Magnesium Mg++AnionsNegatively chargedChloride Cl-Phosphate PO4-Bicarbonate HCO3-Each will be discussed except Bicarbonate as that plays a role in acid base balance which will be covered in NR33

57 Critical Thinking Potassium IV additivesWhich of the following interventions will thenurse undertake when administeringparenteral K additives?Monitor the IV site for phlebitisPlace on cardiac monitor if > 10 mEqAssure of adequate mixing of K in solutionMonitor for elevated K levelsMonitor for decreased Na levelsAdminister potassium by slow IV push methodNEVER!!!

74 Critical Thinking - NCLEXThe nurse is caring for a client with renal failure whose magnesium level is 3.6 mg/dL. Which of the following signs would the nurse most likely expect to note in the client based on this Mg level?TwitchingHyperactive reflexesIrritabilityLoss of deep tendon reflexes

75 Electrolyte homeostasisThis means to maintain balance… to control by balancing the dietary intake of electrolytes with the renal excretion and reabsorption of electrolytes

77 Summary Fluid compartments in the body must balanceBody systems regulate F&E balanceAssessment of body fluid is important to determine causes of imbalanceInterventions for imbalances are based on the cause